Subir Sachdev

Research Interests

My research describes the connection between physical properties of modern quantum materials and the nature of quantum entanglement in the many-particle wavefunction. I have made contributions to the description of the diverse varieties of entangled states of quantum matter. These include states with topological order, with and without an energy gap to excitations, and critical states without quasiparticle excitations. Many of these contributions have been linked to experiments, especially to the rich phase diagrams of the high temperature superconductors.

Extreme examples of complex quantum entanglement arise in metallic states of matter without quasiparticle excitations, often called strange metals. Remarkably, there is an intimate connection between the quantum physics of strange metals found in modern materials (which can be studied in tabletop experiments), and quantum entanglement near black holes of astrophysics. I have exploited this connection to advance our understanding of experiments on strange metals

Positions Held

Professor of Physics at Harvard University, July 1, 2005 to June 30, 2015

Professor of Physics and Applied Physics at Yale University, July 1, 1995 to June 30, 2005

Associate Professor (tenured) of Physics and Applied Physics at Yale University, July 1, 1992 to June 30, 1995

Associate Professor (term) of Physics and Applied Physics at Yale University, July 1, 1989 to June 30, 1992

Assistant Professor of Physics and Applied Physics at Yale University, July 1, 1987 to June 30, 1989

Postdoctoral Member of Technical Staff at AT&T Bell Laboratories, Murray Hill, NJ from September 1, 1985 to August 31, 1987.

Awards

Lars Onsager Prize, American Physical Society, 2018.
Citation: for his seminal contributions to the theory of quantum phase transitions, quantum magnetism, and fractionalized spin liquids, and for his leadership in the physics community.

Dirac Medal for the Advancement of Theoretical Physics, awarded by the Australian Institute of Physics, the University of New South Wales, and the Royal Society of New South Wales, 2015, from an endowment set up by Dirac.
Citation: The Dirac Medal was awarded to Professor Sachdev in recognition of his many seminal contributions to the theory of strongly interacting condensed matter systems: quantum phase transitions, including the idea of critical deconfinement and the breakdown of the conventional symmetry based Landau-Ginsburg-Wilson paradigm; the prediction of exotic 'spin-liquid' and fractionalized states; and applications to the theory of high-temperature superconductivity in the cuprate materials.

Elected to the U.S. National Academy of Sciences, April 2014.
Citation: Sachdev has made seminal advances in the theory of condensed matter systems near a quantum phase transition, which have elucidated the rich variety of static and dynamic behavior in such systems, both at finite temperatures and at T = 0. His book, Quantum Phase Transitions, is the basic text of the field.

Exotic metals in graphene and the high temperature superconductors
(New questions in quantum field theory from condensed matter theory, International Center for Theoretical Sciences, Bengaluru, December 28, 2015)

Emergent gauge fields and the high temperature superconductors
(Unifying physics and technology in light of Maxwell's equations, The Royal Society, London, November 16, 2015)

Quantum Entanglement and Superconductivity
(Dirac Lecture, University of New South Wales, Sydney, Australia, September 1, 2015)

The two unusual metals in the cuprates
(Moore Foundation EPIQS Symposium, Sausalito, August 6, 2015)

Metals with long-range entanglement
(University of New South Wales, Sydney, Australia, August 31, 2015)

The metallic states of the cuprates
(School on Strongly Coupled Field Theories for Condensed Matter and Quantum Information Theory, International Institute of Physics, Natal, Brazil, August 13-14, 2015)

The "normal" states of the cuprates
(Summer School on Emergent Phenomena in Quantum Materials, Cornell University, August 4, 2015)